In the field of endodontics, one of the most important and delicate procedures is that of cleaning or extirpating a diseased root canal to provide a properly dimensioned cavity while essentially maintaining the central axis of the canal for filling of the canal void and capping of the tooth. When done properly, this step enables substantially complete filling of the canal with biologically inert or restorative material without entrapping noxious tissue in the canal that could lead to failure of the therapy.
In a root canal procedure, the dentist removes diseased tissue and debris from the canal prior to filling the canal with a biologically inert or restorative filling material. In performing this procedure, the dentist must gain access to the entire canal, shaping it as appropriate. Many tools have been designed to perform the difficult task of cleaning and shaping root canals. Historically, dentists have used endodontic instruments, such as files, to remove the soft and hard material from within and adjacent the root canal area. These endodontic instruments are typically tapered rods with helical cutting edges on a working portion generally adjacent a distal end of the rod. The proximal end of the rod typically includes a handle which is adapted to be gripped by a user or by a hand-held device. The user or hand-held device rotates the endodontic instrument within the root canal, wherein the helical cutting surfaces remove material from the walls of the root canal as the file is rotated.
Due to the delicate nature of endodontic procedures, minor variations of movement of an instrument by a dentist may have substantial effects on a patient and the success of a given operation. More substantial movements by a dentist such as, for example, a slip of the thumb and index finger, could cause irreparable damage to a tooth or mouth structure. Ultimately, the more predictable a particular sized endodontic instrument is to a dentist, the less likely such dentist will make errors during an endodontic procedure using the familiar instrument.
Additionally, use of hand-held automated devices to rotate endodontic instruments, while often more efficient, can sometimes limit the ability of a dentist to perform the most detailed portions of a root canal procedure. This is at least partly due to the lack of tactile feedback that is present during root canal procedures in which instruments are manually rotated. Accordingly, dentists sometimes interchange between manual and device rotated instruments during a root canal procedure, which requires duplicative instruments, one set for manual use and one set for use in a device. It would be preferable for a single set of instruments to be usable manually and in a hand-held device.
What is needed therefore is a universal endodontic instrument that may be used by hand or used with a dental rotation device. Moreover, what is needed is a safety barrier to prevent a dentist's thumb and/or finger(s) from slipping on the handle of an endodontic instrument.